The invention concerns a device for transference of a fabric strip from a deposit station to a support base, according to the main idea in claim 1.
A device of this sort is established, for example, in U.S. Pat. No. 4,281,606. The established device serves to transfer a flap of fabric from the deposit station to a fabric clamp. This fabric clamp secures the flap and the fabric (onto which the flap is to be sewn) to the sewing machine table. According to the established device, the transfer clamp seizes the end of the fabric strip. The strip's end projects over the edge of the support plate. The transfer clamp then pulls the end of the fabric strip with a swinging movement under and through a flap clamp. The flap clamp is attached to the fabric clamp. Now the fabric strip can be held securely by the flap clamp on the fabric clamp. A device similar to the aforementioned device, for transference of a piping strip to a folded device, is disclosed in U.S. Pat. No. 3,747,544. With this device, a transfer clamp, which is adjustable, seizes the end of the piping strip as it projects from the support plate. The device then deposits the piping strip's end into a folding device.
In both cases, the fabric strip is transfered unchanged from the deposit station to the support base. However, there are cases in which the fabric strip must be folded before being placed onto the support base, or onto the fabric. For example, it is undesirable to simply stitch the fabric strips forming a pocket trim on the actual pocket seam in a pair of pants. Otherwise, the person wearing the pants can easily catch his hand on the threads of this seam and inadvertantly rip the seam out. Instead, the pocket trim in the seam area should be first folded and then sewn in along with the actual pocket. For this process, the seamstress must first fold the fabric strips (the trim) and lay them in their folded condition onto the actual pocket. Both pieces must then be fed by hand through the sewing machine. This process necessitates a considerable amount of time and care, because, due to the narrowness of the folded strips, they can easily become unfolded. Also, the seam must run very close to the fold.
It is an object of this invention to provide a device of the aforementioned sort which is able to take a fabric strip from the deposit station and lay it, in a folded condition, onto the support base.
As it lies on the stop ledge on the support plate, the fabric strip arches up almost imperceptibly over the folding bar. The arched segment of the strip projects into the opening of the transfer clamp. If this transfer clamp is closed, the fabric strip will be folded and held securely in the folded position. In this position of the transfer clamp, the fabric strip cannot be deposited without the danger of it unfolding again as soon as the clamp is opened. For this reason, the transfer clamp will be swung, so that the area where the fabric strip is affixed between the clamp ledges is no longer vertical to the support's plane, but instead is situated horizontal to this plane. This will occur either before or during the transition of the transfer clamp from its receiving position to its delivery position. In this horizontal position, the fabric strip can be layed flat onto the support base. The strip can also, for example, be accepted by a fabric clamp which leads the strip, together with the fabric onto which the strip will be sewn, to the sewing station.
Here it is advantageous if the clamping ledges (which work together to hold the segment of fabric strip and which face the support base in the delivery position) are fashioned from thin plates. This way, there will be only an unnoticeable gradation between the support base and the clamp ledge which lies on this base. The fabric, even in its folded condition, can then be laid almost completely level on the support base.
If only one of the clamp ledges is moved to hold the fabric, while the other clamp ledge rests across from the support plate, then it is advisable to mount the folding bar so it is adjustable against resilience. The folding bar should be adjustable vertically and also parallel to the support plane of the support plate. Otherwise, it would be necessary to place the clamp ledge (which is resting during the clamping process) on the support plate exactly next to the folding bar while placement of the transfer clamp occurs. This must be done in order to be able to subsequently close the clamp. By means of the resilient mounting of the folding bar, it would be nevertheless taken along as the clamp closes and slid out from between the folded fabric as the transfer clamp lifts from the support plate. Then it will turn by means of its resilience again back to its initial position. Because of the folding bar's movement allowance, no essential adjustment problems arise in adjusting the receiving position of the transfer clamp relative to the folding bar.
In order to adjust to the width of the end segments that will be seized by the transfer clamp, the folding bar may be so arranged, that it is vertically adjustable to the support plane of the support plate. The folding bar, fashioned, for example, from a steel plate, is appropriately screwed onto its mounting. The screws penetrate the folding bar through slots, so that the bar may be adjusted.
To enable lying another piece of fabric (upon which the transferred fabric strip will be placed) ready under the support plate, it is advisable to manufacture the support plate from a transparent material. In this way, the laborer's view is unobstructed while he arranges the fabric.
In the preferred construction, the clamp ledge is mounted on a bow. The bow is on a pivotal axle. Here, the transfer clamp is adjustable by means of a cylinder. This cylinder seizes both a piece attached to the bow and this clamp ledge. The other clamp ledge is appropriately led to the first clamp ledge which is attached to the bow. This second clamp ledge is adjustable, just as the transfer clamp, to open and close. This adjustment is achieved by a second cylinder, which is attached to both clamp ledges. Therefore, the clamp ledges are moved straight across from each other as the transfer clamp opens and closes.
Adjustment of the transfer clamp from the receiving position to the delivery position, and vice versa, can be achieved as follows:
The bow (adjustable to height) is led to a frame. The bow is adjustable by a third cylinder which operates between the frame and the bow. The frame, on its mount, is pivotably mounted to an axle parallel to the support plate. This is adjustable by means of a fourth cylinder which operates between the mount and the frame. Hereby, the support plate (relative to the support base) is tilted to an angle corresponding to the pivotal angle of the frame. After closing the transfer clamp in the deposit station, the transfer clamp will then, for example, be lifted from the support plate and subsequently be swung back away. As a result, the frame on its mount will be swung far enough so that the transfer clamp can be lowered going by the support plate onto the support base. The fabric strip lying on the support base can then, for example, be clamped onto the support base, in its folded condition, by a fabric clamp. Hereby the transfer clamp can be opened and lifted from the support base.
With the device described above, it is possible to execute a problem-free and absolutely exact deposit of a fabric strip (in its folded condition) to a support base. The laborer must simply arrange the first piece of fabric on the support plate, and then lay the fabric strip (which is to lie on the first piece of fabric) onto the support plate. The folding and transfer of the fabric strip, as well as the sewing of both fabric pieces, result automatically from there.